Disk mill

ABSTRACT

The specification discloses a disk mill in which a pair of opposed disks are mounted in a casing with the disks having an abrasive pattern of novel design on the opposite faces thereof. One disk is held stationarily but adjustably in the casing while the other disk is rotatable therein and is under spring load so as to be yieldable in the event hard foreign particles are entrained in the material being milled. The rotatable disk has a peripheral blade which picks up material from the bottom part of the casing and conveys it upwardly toward the top toward a tangential discharge opening. Finely milled material will pass through the discharge opening whereas coarser material will drop back into the mill for further treatment by the disks.

United States Patent [191 Mendoza 1 DISK MILL [76] Inventor: Fausto Celorio Mendoza, Cumbres de Acultzingo 185, Lomas de Chapultepec, Mexico City, Mexico [22] Filed: Aug. 2, 1971 [21] Appl. No.: 168,189

[30] Foreign Application Priority Data Mar. 15, 1971 Mexico 125691 [52] 11.8. CI. 24l/26l.3, 241/296 [51] Int. Cl. B02c 7/12 [58] Field of Search 241/247, 255, 256, 241/260, 296, 261.2, 261.3

[56] References Cited UNITED STATES PATENTS 2,743,874 5/1956 Asplund 241/256 X 3,589,629 6/1971 Michel 241/256 X 3,049,307 8/1962 Dalzell, Jr. 241/255 2,172,151 9/1939 Dick 241/247 166,419 8/1875 Smith 241/296 [451 Sept. 25, 1973 261,099 7/1882 Lehmann 241/296 Primary Examiner-Granville Y. Custer, Jr.

Attorney-Jeffers & Rickert [5 7] ABSTRACT The specification discloses a disk mill in which a pair of opposed disks are mounted in a casing with the disks having an abrasive pattern of novel design on the opposite faces thereof.

One disk is held stationarily but adjustably in the casing while the other disk is rotatable therein and is under spring load so as to be yieldable in the event hard foreign particles are entrained in the material being milled.

The rotatable disk has a peripheral blade which picks up material from the bottom part of the casing and conveys it upwardly toward the top toward a tangential discharge opening. Finely milled material will pass through the discharge opening whereas coarser material will drop back into the mill for further treatment by the disks.

11 Claims, 5 Drawing Figures PATENTED SEPZS I973 SHEET 2 BF 2 DISK MILL This invention relates to mills and, more especially, improvements in the disks thereof and in the arrangement and cooperation of the various mill components.

Disk mills are known and are currently employed in a wide variety of milling operations such as in the manufacture of paint pigments, cement, flours from different grains, in the reduction to fine powder of many materials used in such diverse industries as chemistry and in the resin and plastics industry, and the like.

As is well known, a conventional milling operation is carried out by passing the materials to be milled through mill disks for a first size reduction, whereupon the materials are repeatedly passed back through the same mill or through other serially arranged mills until the desired material fineness is achieved.

When a single mill with a series of successive passes of the materials therethrough is used, and also when a series of mills with a single pass through each is em ployed, many drawbacks are encountered which make the milling operation time and money consuming and the yield is low as compared with the time and the investment required for the machinery and the maintenance thereof. A

Thus, for example, with relatively hard materials, as is the case with materials of a mineral origin, the rate such that, once the abrasive design thereon has been reduced as to milling capacity, these disks can be discarded and replaced by others of the same type, or the abrasive design thereon can be renewed so as to make the disks again usable.

Another object of the present invention is to provide a novel and particularly efiicacious abrasive design for of wear of the abrasive design on the disks is high,

the so-called integral flour, i.e., a flour composed both i of the cereal fecula and husk, can never be obtained, inasmuch as it has not, heretofore, been possible efficiently to process the husk in these mills and thus, in order to prepare the so-called integral flour, it has, in the past, been necessary to mill the husks separately and to mix it with the previously obtained flour.

It is often observed that if a foreign material having a certain size and of a hardness greater than that of the materials being milled, such as, for instance, screws, pebbles, etc., is present, then the material becomes trapped between the disks or is crushed thereby, always to the injury of the abrasive design on the disks, a fact which impairs the quality of the milling operation. Such damage to the disks results in an uneven reduction of the materials being milled.

The present invention proposes to eliminate or, at least, to minimize, the above drawbacks and disadvantages of disk mills of the prior art.

Accordingly, it is the general object of this invention to provide an improved disk mill whereby it will no longer be necessary to effect a series of separate passes for the materials to be milled so as to reduce them to the fineness desired.

It is another object of this invention to eliminate the need for a serial arrangement of mills for obtaining the desired fineness of the materials to be milled.

Another objectof this invention is to provide an improved disk mill, of the above-mentioned type, which uses disks that may be of the disposable" type, i.e.,

the disks employed with the improved disk mill of this invention, which will permit the automatic re-passing of the materials that are being milled, so as to impart the desired fineness to said materials.

Another object of the present invention is to provide, together with the improved disks mentioned above, a removing-blade arrangement on one of the disks for the purpose of removing and scraping portions of unmilled, or not fully milled material, lodged in a lower part of the mill, to cause the material again to pass through the disks.

A further object of the presentinvention is to provide inside the mill a storing or containing portion for the materials being processed, from which storing or containing portion the said disks and blade arrangement will be able to pick up portions of the material to process said portions of material again, by which means the continued milling of the materials being processed is secured, until the desired fineness thereof is attained.

It is a further object of the invention to provide a system of pressure and stress-absorption control in the disk mill of the present invention, making it possible to control the separation of the improved disks from each other and to absorb the stresses thereon whenever a particle of a greater size and hardness than that being processed is present, so as to avoid, or minimize, injuries to the abrasive design or pattern of the disks.

These and other objects and advantages of the present invention willbecome more apparent upon reference to the following detailed specification taken in connection with the accompanying drawings in which:

FIG. 1 is an edge view of an improved disk element according to the present invention;

FIG. 2 is a plan view of the same disk showing the improved design or pattern thereon and illustrating the arrangement of different portions thereof;

FIG. 3 is a sectional view taken approximately along.

line 3-3 of FIG. 2;

FIG. 4 is a front view of a mill showing the discharge mouth and the fastening and feeding devices for one of the disks; and

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4.

BRIEF SUMMARY OF THE INVENTION According; to the present invention, a generally cylindrical casing is provided with a tangential discharge near the top and a central inlet opening in one end wall. A stationary disk in the casing has a central hole through which fed material is introduced, while a rotatable disk in the casing is arranged in opposing relation to the stationary disk.

The disks on their opposite faces have an abrasive pattern thereon including grooves so that material in the cases is milled between the disks, while material collecting in the bottom of the casing is in part lifted upwardly by the grooves in the rotating disk for remillmg. p

The rotating disk also has a blade thereon which engages material in the bottom of the casing and lifts it upwardly and, if the material is finely ground, it will be expelled through the discharge from the mill, while particles less finely ground will fall back into the mill for again being treated by the disks.

DETAILED DESCRIPTION OF THE INVENTION It will be noted that the following description is not to be taken in a limiting sense, and that both the terminology used and the illustrations shown are merely illustrative of a presently preferred embodiment. It should, moreover, be noted that, for the purposes of the description, specific reference is made to the use of the mill of this invention to the processing of grains such as rice, lentils, corn, wheat, barley, coffee, etc.

However, the inventive principles disclosed are not limited to the field of grains, since, as previously explained, this type of mills can be employed in a great variety of totally different applications and for different materials.

The preferred structure of the disks used in the disk mill of the present invention will be seen in FIGS. 1 to 3 of the drawings. As will be clearly seen in FIG. 2, the design, or pattern, with which the disks of the present invention are provided differs substantially from conventional patterns on disks of prior art mills. The design of the working side of a typical disk, clearly shown in FIGS. 1 to 3, consists of different clearly defined zones, each of which has a specific purpose, as will hereinafter be discussed in detail.

Referring more especially to FIG. 2, the disk of the present invention, shown generally at 10, is of a substantially circular configuration and in the center thereof is provided with a through bore 12, which communicates directly with a central conical portion 14 that extends radially outwardly from bore 12. This central conical portion 14 at the outer limit thereof is met by a plurality of passages 16 that alternate with groove groups 18 substantially parallel to the passages 16, and which, at the opposite edge, are limited by shorter passages 20 limited, in turn, by another series of grooves 22 extending angularly to the passages 16 and 20 and the first series of grooves 18. i

The grooves 18 and the passages 16 are obliquely inclined in respect of the diameter of disk 10, said inclination being in a sense that follows the direction of rotation of the disk. Said passages 16 and grooves 18 extend from the outer periphery of the central conical portion 14 to the outer periphery of the disk in the manner shown in FIG. 2.

Passages 20, in turn, which are parallel to passages 16 and are separated therefrom by the series of grooves 18, extend from the outer periphery of the disk to a point 21 separated from the outer periphery of the central conical section 14 by a portion of the series of grooves 18 and by a portion of the series of grooves 22, and with its inner edge 26 follows the line or direction of grooves 22. The plurality of grooves 22 come out forming an angle from the plurality of grooves 18, with the exception of the interposed portion of passage 20, from point 21 to the periphery of the disk 10.

At a point on the outer periphery thereof, the disk 10 is provided with a blade device 11 which projects radially outwardly therefrom and, as will clearly be seen in FIGS. 1 and 5, extends perpendicularly to the disks a certain distance beyond the face of the disk 10 having the above-mentioned design for a purpose to be described.

A complete description of the manner inwhich the mill of the present invention operates will be given at a later stage of this disclosure, and there is now described the operation of the disk to explain the reasons for the varying portions of the above described design thereof.

As is known in the art, mill disks are fed through central bore 12, so that the materials to be processed enter the disk through the central conical portion 14, whence the material will proceed outwardly through the pattern or design until it finally emerges at the outer periphery of the disk. With the disk mill of the present invention, the disks 10 operate in respect of material supply and flow, in the same manner.

However, due to the arrangement of the passages 16, a plurality of particles, grain, for example, can freely pass downwardly along the passages 16 which are vertically disposed as the mill is fed through the bore 12 and while the mill disks remain motionless. The purpose of the free passage of the grains through passages 16 will be discussed more in detail in connection with FIG. 5.

Although the grains can pass freely through passages 16 in downward direction while the disks remain motionless, once the disk represented in FIG. 2 is caused to turn counterclockwise (working direction) the grains will be frictionally driven towards the first series of grooves 18 and partly also by gravity as the passage 16 gradually ascends from a downwardly extending position to a horizontal position.

The grains will now be crushed under the action of this plurality of grooves 18, and part of this material will emerge from the outer end of this grooved portion 18, whilst another part will transversely cross the whole of the grooved portion 18 and then enter the second passage 20.

If this passage 20 is in a vertical position, the partially milled material will descend along said portion and fall outside the passage 20. If, however, the passage has an inclination of about 45 degrees, then the material will slide along the edge of the passage 20 closest to the second series of grooves 22 and, as the counterclockwise displacement of the passage 20 continues, said material will be trapped by the grooved portion 22, to be there additionally milled.

In view of the angular arrangement between this grooved portion 22 and the passage 20, part of the partly milled material reaching this point will merely cross this portion 28, the thickness of which is reduced, and then fall again in the following passage 16, whence it can again advance through the next grooved section 24 and reach then the following passage 20 and so on until the material emerges from the periphery of the disk.

There is, however, another totally different function performed by the disks 10:

Due to the inclination or obliqueness in the sense of rotation of the passages 16 and 20, these passages, when going through the lowermost position thereof; this position being one in which the passages are in contact with an unmilled or partly milled or mixed material deposit in a chamber at the bottom of the disks act as buckets and pick up a portion of this deposit and lift it to the position necessary to cause it to pass through the grooved portion 18 or 22 immediately following, whereupon the material again proceeds along the previously explained path.

By this additional function, the recirculartion of the materials contained in the said deposit, whether unmilled or partly milled, is automatically effected, and which recirculating operation will be repeated as many times as necessary until the material reaches the desired degree of fineness for being discharged'from the mill. 1

Referring now to FIGS. 4 and 5, the complete arrangement of the improved mill of the present invention will be seen. v

The mill is formed with exterior casing portions 30, 30', within each of which one of the disks 10, of the mill is arranged. These disks are centered about a shaft 32 extending through both disks. One of the disks, 10', is fixedly attached to shaft 32 by fastening means 33, whereas the shaft passes freely through disk 10 which is fixedly but adjustably attached to the casing 30.

Fastening screws 71, extending radially through casing portion 30, engage disk 10 and hold the disk in the proper position for cooperation with the rotary disk 10'. Screws 71 provide for adjustment of disk 10 in a plane perpendicular to the axis of shaft 32.

There is additionally provided a plurality of aligning screws 72 that make it possible to control the axial alignment of the disk 10. Screws 71 extend through the radial wall of the casing portion 30, whereas the aligning devices 72 extend through the peripheral wall of the casing portion 30.

Casing portion 30 carries a hopper 36 through which the material to be milled is fed, which hopper is traversed by the shaft 32. The hopper 36 extends through the casing wall and communicates with a helicoidal carrier 38 for carrying the fed material to the central conical portion 14 between the two disks. Some of the material may fall between disk 10 and the adjacent wall of casing portion 30 to form a material deposit which fills up to an adequate distance so as to enable the rotary disk to perform the above discussed function of a bucket.

Both the feed screw 38 and the shaft 32 and, consequently, the disk ,10', are actuated by a motor (not shown) which drives shaft 32 through the pulley 34.

As previously explained, pan of the material fed to zone 14 will fall by gravity through the passages 16, whereas part of the material will be distributed gradually in the circumferential direction.

Once the desired deposit is achieved, the motor is started, whereby the disk 10 will commence to turn carrying out the above-mentioned milling and material recirculating functions. Meanwhile, blade 11 will begin to turn and remove the material from the deposit 40 each time it dips therein.

Thus, a partly crushing function is obtained as a result of the blades repeated beating, and at the same time, as the blade 11 leaves the deposit portion 40, it lifts part of the material with it. If this material is not totally ground material, it will not be drivenout of the mill, but will fall back by gravity.

In the case of a material having a fine powder consistency, however, the rotating blade, as it lifts the material out of the deposit 40, will permit the air current generated by the rotation of the disk 10' to lift the fine material and to displace it towards discharge 70 tangentially disposed to the periphery of the disk, at a height adequate for the fine material alone to be driven out therethrough, whereas all of the material not finely ground will fall again into the material deposit 40 to be newly milled, which operation will be repeatedautomatically as many times as necessary to reduce the material to the desired degree of fineness.

The end of shaft 32 which is opposite the end on which pulley 34 is mounted, extends out through the radial wall of easing portion 30', as at 42 and through a bearing 46. A stop plate 48 is arranged adjacent bearing 46 and acts as a stopfor one end of a spring 50 extending between said plate 48 and a receiving plate 52 that engages the opposite end of the spring.

End plate 52 is spaced froma fixed plate 54 mounted on base member 44. A screw58, or similar device, extends through plate 54 and abuts plate 52 .while, on the free end of screw 58, a handle or any other adequate manual device is attached to permit the screw 58 to be turned to adjust the position of plate 52, thus imparting a greater or lesser tension to the spring 50, so as to produce an accordingly higher or lower milling action of disk 10.

The above described mechanism also serves to absorb the stresses placed on the disk 10' and opposed disk 10, when a particle that is thicker than the material being ground by the mill, and of harder consistency, is present, inasmuch as the spring will allow the disk 10' to move to a certain extent relative to disk 10, thus permitting this thicker, harder particle to move downwardly without the disks being injured or impaired. in a like manner is achieved a stress-absorption action and injury to the disks by foreign matters present inthe milling operation is minimized. r

The material of which the disks are made may be any material of a hardness suitable for grinding'the materials involved while, at the same time, allowing for disposal of said disks, if so desired, after the abrasive design thereof has been reduced in its milling capacity. Disks 10 and 10', although of the same design, are, however, diflerent, inasmuch as disk 10 presents a central opening 12 of a greater diameter than disk 10 and lacks the blade 11. Otherwise, both disks are identical.

The dimensions of the disks are a direct function of the linear speed of rotation of the periphery thereof and, consequently, an inverse function of the speed of rotation of shaft 32, the relation selected being such that the milling function of the disks, the bucket function of the passages 16 and 20, and the beating and lifting functions of the blade 11 are all carried out in a manner that is highly satisfactory, without impairment of any of these operations.

In the preferred embodiment of the present invention, this mill is used to grind grains or any type of cereal, and the milling thereof has been so satisfactorily accomplished that now for the first time in the art a truly integral flour can be obtained from these cereals, inasmuch as the cereal husk will have been ground to a consistency that equals that of the flour after a plurality of passes thereof through the mill, its flint-like quality notwithstanding, and once this husk has been ground, it will likewise be expelled] from the interior of the mill towards the exit in the same manner as previously explained for the starch flour.

It will be noted that, if the disks are formed identically, the passage elements formed therein between the groups of grooves would be disposed in intersecting relation since the one disk is reversed relative to the other.- This intersecting relation of the passage elements and of the groups of grooves would also permit the disks to be pressed against each other, to obtain a fine milling action without the grooves on one disk engaging those on the other.

It will further be noted, on reference to FIGS. 1 and 3, in particular, that the passage elements, when viewed in the radial direction, incline from one side to the other.

Modifications may be made within the purview of the appended claims. What is claimed is:

l. A disk mill comprising, in combination, a cylindri cal casing having the axis horizontal and having a tangential discharge opening in an upper portion thereof and a central feed opening in one end wall, a nonrotatable disk in the casing adjacent said one end wall and having a central bore communicating with said feed opening, a rotatable disk in the casing adjacent the other end wall of said casing, said disks forming a milling region therebetween, each disk on the side facing the other having a conical depression, each disk on the side facing the other disk having a plurality of groups of grooves formed therein with the grooves in each group being parallel, passage elements formed in the disks between adjacent groups of grooves and extending from the peripheries of the disks inwardly, alternate ones of said passage elements extending from the periphery of the conical depression of the respective disk to the periphery of the disk, the others of said passage elements terminating radially outwardly from the periphery of a respective group of grooves being disposed at the radially inner end of each other passage element, said passage elements being obliquely inclined in the direction of rotation of said disks, said casing having a lower portion forming a chamber for receiving material passing through the mill and into which said disks extend, said passage elements when passing through said chamber serve as buckets to pick up a portion of the material being milled to lift it to a position to again pass to the milling region.

2. A disk mill according to claim 1 which includes a gap between said nonrotatable disk and said feed opening to permit some of the material fed through said opening to drop directly into said chamber.

3. A disk mill according to claim 1 in which said passage elements alternate with said groups vof grooves in the circumferential direction of said disks.

4. A disk mill according to claim 1 in which pairs of said passage elements are parallel to each other and to the grooves of the group on one side thereof while the grooves of the group on the other side thereof are at an angle to the respective pair of passage elements.

5. A disk mill according to claim 1 which includes a shaft extending through said feed opening and said bore in said nonrotatable disk and fixed to said rotatable disk, and a feed screw on said shaft leading from said inlet opening through the bore in said nonrotatable disk.

6. A disk mill according to claim 1 wherein a blade extends outwardly from the periphery of the rotatable disk to partly crush the material in the chamber and to lift part of the material upwardly for recycling through the milling region.

7. A disk mill according to claim 1 which includes connecting means adjustably connecting said nonrotatable disk to said casing and providing for radial and axial adjustment of the position thereof in said casing.

8. A disk mill according to claim 7 in which said connecting means includes first screws extending radially through said casing and threadedlyengaging the peripheral portion of said nonrotatable disk and second screws threaded through said one end wall of said casing and abutting the side of said nonrotatable disk which faces said one end wall.

9. A disk for use in a disk mill and comprising; a circular member having oppositely facing axial faces and a periphery, one of said faces having a plurality of groups of grooves formed therein and distributed circumferentially thereon and passage elements formed in said one face between adjacent ones of said groups of grooves, adjacent pairs of said passage elements being parallel to each other and to the group of grooves therebetween and on one side thereof and at an angle to the group of grooves on the other side thereof, the one of each pair of passage elements nearest said one side thereof extending from the central region of the disk to the periphery thereof while the other passage element of each pair is interrupted at the inner end by said group of grooves on said other side of said pair of passage elements and extends therefrom to the periphery of the disk, each of said passage elements being inclined in one and the same direction relative to a radius of the disk passing through the outer end of the respective passage element, each said passage element when viewed radially continually diminishing in depth from one side toward the other side.

10. A disk according to claim 9 in which said disk includes a central conical recess which communicates at the periphery with the radially inner ends of said passage elements on said one side of each pair thereof.

11. A disk according to claim 10in which said recess at the periphery thereof communicates with at least grooves.

l i I I 

1. A disk mill comprising, in combination, a cylindrical casing having the axis horizontal and having a tangential discharge opening in an upper portion thereof and a central feed opening in one end wall, a nonrotatable disk in the casing adjacent said one end wall and having a central bore communicating with said feed opening, a rotatable disk in the casing adjacent the other end wall of said casing, said disks forming a milling region therebetween, each disk on the side facing the other having a conical depression, each disk on the side facing the other disk having a plurality of groups of grooves formed therein with the grooves in each group being parallel, passage elements formed in the disks between adjacent groups of grooves and extending from the peripheries of the disks inwardly, alternate ones of said passage elements extending from the periphery of the conical depression of the respective disk to the periphery of the disk, the others of said passage elements terminating radially outwardly from the periphery of a respective group of grooves being disposed at the radially inner end of each other passage element, said passage elements being obliquely inclined in the direction of rotation of said disks, said casing having a lower portion forming a chamber for receiving material passing through the mill and into which said disks extend, said passage elements when passing through said chamber serve as buckets to pick up a portion of the material being milled to lift it to a position to again pass to the milling region.
 2. A disk mill according to claim 1 which includes a gap between said nonrotatable disk and said feed opening to permit some of the material fed through said opening to drop directly into said chamber.
 3. A disk mill according to claim 1 in which said passage elements alternate with said groups of grooves in the circumferential direction of said disks.
 4. A disk mill according to claim 1 in which pairs of said passage elements are parallel to each other and to the grooves of the group on one side thereof while the grooves of the group on the other side thereof are at an angle to the respective pair of passage elements.
 5. A disk mill according to claim 1 which includes a shaft extending through said feed opening and said bore in said nonrotatable disk and fixed to said rotatable disk, and a feed screw on said shaft leading from said inlet opening through the bore in said nonrotatable disk.
 6. A disk mill according to claim 1 wherein a blade extends outwardly from the periphery of the rotatable disk to partly crush the material in the chamber and to lift part of the material upwardly for recycling through the milling region.
 7. A disk mill according to claim 1 which includes connecting means adjustably connecting said nonrotatable disk to said casing and providing for radial and axial adjustment of the position thereof in said casing.
 8. A disk mill according to claim 7 in which said connecting means includes first screws extending radially through said casing and threadedly engaging the peripheral portion of said nonrotatable disk and second screws threaded through said one end wall of said casing and abutting the side of said nonrotatable disk which faces said one end wall.
 9. A disk for use in a disk mill and comprising; a circular member having oppositely facing axial faces and a periphery, one of said faces having a plurality of groups of grooves formed therein and distributed circumferentially thereon and passage elements formed in said one face between adjacent ones of said groups of grooves, adjacent pairs of said passage elements being parallel to each other and to the group of grooves therebetween and on one side thereof and at an angle to the group of grooves on the other side thereof, the one of each pair of passage elements nearest said one side thereof extending from the central region of the disk to the periphery thereof while the other passage element of each pair is interrupted at the inner end by said group of grooves on said other side of said pair of passage elements and extends therefrom to the periphery of the disk, each of said passage elements being inclined in one and the same direction relative to a radius of the disk passing through the outer end of the respective passage element, each said passage element when viewed radially continually diminishing in depth from one side toward the other side.
 10. A disk according to claim 9 in which said disk includes a central conical recess which communicates at the periphery with the radially inner ends of said passage elements on said one side of each pair thereof.
 11. A disk according to claim 10 in which said recess at the periphery thereof communicates with at least some of the inner ends of the grooves of each group of grooves. 